1. Field of the Invention
The invention relates to an apparatus and a method for contactless detection of the rotational angle of a rotatable element.
2. Description of the Prior Art
From German Patent Disclosure DE-A 100 17 061, an arrangement for contactless detection, in particular, of the rotational angle of a rotatable element is known, in which by evaluating magnetically variable properties of a sensor array with at least two sensor elements, a magnetic field intensity generated or varied by the rotatable element is detectable in an evaluation circuit and used for ascertaining the rotary position; one sensor element works by using the magnetoresistive effect, and at least two further sensor elements operate by utilizing the Hall effect, and the evaluation circuit serves the purpose of logical linkage of the three sensor signals thus obtained.
From Japanese Patent Disclosure JP-A 2004085482, an apparatus for detecting rotational angles over more than one revolution of a rotating shaft is also known it includes a first means for angle detection, a conversion means for converting a rotating motion into a longitudinal motion, and a further means for detecting a linear position of the rotating shaft by means of a spacing measurement.